The Mtfr1 has been confirmed as a targeted gene of miR-324-5p through miRTarBase software and western blot. miR-324-5p protects against oxidative stress-induced EPCs injury by regulating Mtfr1. Knocking down Mtfr1 suppresses mitochondrial fission, apoptosis, and myocardial infarction. Mtfr1 is a direct target of miR-324-5p, and miR-324-5p attenuates mitochondrial fission, cardiomyocyte apoptosis, and myocardial infarction by suppressing Mtfr1 translation. Mtfr1 (mitochondrial fission regulator 1), is a gene involved in the regulation of antioxidant activity in the mouse testis. Mtfr1 protects the male gonads against oxidative stress. Mtfr1/Chppr is a nuclear gene coding for a mitochondrial protein capable of inducing fission of this organelle in a sequence-specific manner.